Flash light plug



May 10, 1932. H T 1,857,604

FLASH LIGHT PLUG Filed Dec 17. 1926 r I I r 51 vwewfoz as m wow Patented May 10, 1932 UNITED STATES PATENT OFFICE ALBERT I-I. POST, OF WATERBURY, CONNECTICUT, ASSIGNOR TO HENRY HYMAN, OF

BROOKLYN, NEW YORK FLASH LIGHT PLUG Application. filed December 17, 1926.

This invention relates to an electric light plug containing an automatic make and break device by which the electric circuit is automatically interrupted at periodical intervals. The device comprises a plug or base of insulating material having one end thereof provided with a screw shell and a central contact to adapt it to be screwed into a lamp socket and make contact with the terminals thereof, and the other end is provided with openings into which the terminals of a push plug can be inserted. Gontacts are provided in the device for the terminals of the push plug and a thermostatically operated make and break device is located in the plug and interposed in the circuit so that the light or lights connected thereto will go on and off at intervals.

The invention will be understood from the description in connection with the accompanying drawings, in which Fig. 1 is a side elevation of the plug partly in section; and Fig. 2 is a section showing details on an enlarged scale of a modification. In the drawings' reference character 1 indicates a tapered base or plug that is made of insulating material and is provided with a corrugated rim 2 at one end to facilitate screwing the plug into place. A threaded metal sleeve 3 is applied to the other end of the plug 1, and is provided with a flange 4 that rests upon the end of the plug. Longitudinal openings or passageways 5 extend through the plug on opposite sides of the central axis thereof and spring contacts 6 and 7 extend into the openings 5 and have bent ends 6 and 7 respectively, that rest upon the end of the plug 1. A central metal pin 8 is anchored in the end of the base 1. A disc of insulating material 9 is provided with a central hole 10 that fits over the pin 8 and another disc 11 of insulating material is provided with a central hole 12 that fits over the pin 8. A contact pin 14 attached to the bent end of the spring contact 7 extends into a hole 15 through the disc 9.

The upper side of the disc 9 and the lower side of the disc 11 may be provided with recesses or grooves 16 and 17, respectively, to accommodate a make and break device. These recesses or grooves are offset from the Serial No. 155,361.

center of the discs and extend of circles and face each other. A thermal element 18 of well known type made up of contacting strips of metals of diflerent coefficients of expansion is provided at one end with a contact 19 extending into the hole 15 in the disc 9, and an insulating resistance wire 20 to act as a heating element is coiled around the thermal element 18. One end of this wire is connected to the contact 14 and the other end is connected to the metallic element 18. The end of the thermal element 18 opposite the contact 19 is attached to the disc 11 by means of the rivet 21 that extends through the disc 11, and this rivet is connected by the connector 22 to the pin 8. A cap or contact 23 is soldered or otherwise attached to the protruding end of the pin 8 to retain the parts in place on the base 1.

The operation is as follows: The plug is screwed into an ordinary lamp socket with the screw shell 3 making electrical contact with the screw shell of the socket and the contact 23 pressing against the central contact of the socket. A push plug of a lamp cord of the well known type, having parallel metal terminals is pushed so that the terminals enter the openings 5 and make contact with the spring contacts 6 and 7. Current then passes from the screw shell of the lamp socket into the screw shell 3, thence through the spring contact 6, and one terminal of the push plug, wire of the cord, through the filament or filaments of the lamps connected to the cord, thence through the other wire of the cord to the other terminal of the push plug to the spring contact 7 contact 14, heating coil 20, rivet 21, connector 22, contact 23, central contact of the lamp socket to the other side of the circuit. As soon as the heating element 20 becomes heated, the thermal element 18 bends, thus causing the contact 19 to press against the contact 14 and close the circuit through the thermal element 18, lighting the lamps. This also causes the heating coil 20 to be short circuited and cool off. The thermal element will then straighten out to pull the contact 19 away from the contact 14, whereupon current will again go through the heating coil along cords 20, whereupon the thermal element will again become heated and cause the circuit to be closed, and so on, automatically at periodical intervals. In the modification shown in Fig. 2, a rivet 25 attaches the spring contact 7 to the disc 9 of insulating material. Thethermal element of the make and break device is mounted upon a metal disc 26 that fits upon the 10 central: pin;8to make electrical contact therewith, and is provided with lugs or. projections 27 to keep the disc 11 of insulating material, far enough away from the disc 26 to permit movement of the thermal element 15 to make and break the circuit. A rivet 28 extends throughthe metal disc 26and is in. sulatedtherefrom by the, insulating material 29. The thermal element 30 carries a contact 3lat one end andis attached by. means oftherivet 33 at the other end of the metal disc 26. Theheating coil 32 around the thermal element hasone end attached to the rivet 29 and the other end attached to the element 30.; The operation of the make .and break device is similar toithat above described in connection with Fig. 1, so that the circuit is madei and broken perodically at the-contacts 29 and 3l.

It will thus be seen that with this device, 30 the lamps.connectedto. a-lamp' cord that is, provided with aipushrplug can be made to flash from a screw socketsimply by inserting the, device in, the screw socket and plugging in the push plug. Itwill ,also .be clear that the push plug can be inserted into thisdevice first, and the, device can then, bescrewed into. a lamp, socket.

Iclaim:

fiash light plug comprising an insu lating base, a threaded shell on said base adapted tov screw into-a lamp socket, a pair ofv contacts in said baseioneof which is connected to, said shell, a central contact at the end of said plug, a thermostaticallyoperated make and break element connected tosaidcentral v contact,and the other contact of said pair ofi contacts, and a pair'of insulating discs at the end of said base between which saidmake and break-element is located. ALBERT H. POST. 

